Why are parameters in docker.service not passed ?

Issue

Docker systemd is configured with custom docker startup parameters in /usr/lib/systemd/system/docker.service

ExecStart=/usr/bin/dockerd-current \
          --add-runtime docker-runc=/usr/libexec/docker/docker-runc-current \
          --default-runtime=docker-runc \
          --authorization-plugin=rhel-push-plugin \
          --exec-opt native.cgroupdriver=systemd \
          --userland-proxy-path=/usr/libexec/docker/docker-proxy-current \
          $OPTIONS \
          $DOCKER_STORAGE_OPTIONS \
          $DOCKER_NETWORK_OPTIONS \
          $ADD_REGISTRY \
          $BLOCK_REGISTRY \
          $INSECURE_REGISTRY

But docker is started without parameters from systemd file:

root      9961  0.0  2.7 499572 24052 ?        Ssl  13:26   0:00 /usr/bin/dockerd-current -H unix:///var/run/docker.sock --ip-forward=true --iptables=true --ip-masq=true -H tcp://0.0.0.0:4243 --add-registry docker-registry.barmenia.lan:18000 --block-registry docker.io --dns 172.20.223.91 --storage-opt dm.datadev=/dev/datavg/data --storage-opt dm.metadatadev=/dev/datavg/metadata